[Lapack] issues with wrong result..

From: Julien Langou
Date: Thu, 2 Aug 2007 08:08:10 -0600 (MDT)

I guess you get the result from applying directly DGETRI on A ...
Well no, this does not work like this, to compute the inverse of A with
DGETRI, you first need to call DGETRF then DGETRI as explained in the
header of the routine:
* DGETRI computes the inverse of a matrix using the LU factorization
* computed by DGETRF.
Your code should not be muche more harder. Just insert a call to DGETRF
before the call to DGETRI and it should a priori work.
Julien.
For the LAPACKers, try:
A = [ 1 0.5 0.25 ; 0.5 1 0.5 ; 0.25 0.5 1];
U=triu(A); L=tril(A,-1)+eye(3); inv(L*U)
:)
On Thu, 2 Aug 2007, sabhnani@Domain.Removed wrote: